How Does He Sleep Standing Up?

Several years ago while hiking in the mountains of Montana, a
friend of mind and I came around a corner on a trail and came
face-to-face with a horse standing in the middle of the trail.
We had been walking quietly in the hope of seeing wildlife and
found our wildlife to be a domestic horse sound asleep in the
middle of the trail. The horse's eyes indicated he was in a deep
sleep. As we got a little closer to the horse, he woke up, saw
us, and bolted from the trail and galloped across a nearby meadow.
There was no question that he was asleep, standing up, motionless,
and had been that way for some time. "How can he sleep standing
up?" my friend asked.

The fact is that many animals sleep standing up. The bulk of
large animals like horses and elephants causes pressure against
their ribs when they lie down, making breathing difficult. In
these animals, the leg joints lock automatically when they relax,
allowing them to be stable even when asleep. In the case of birds,
the tendons in the leg cause the toes to automatically curl around
a limb when the bird perches. Birds can be asleep and the leg
will stay anchored to the branch. It is only when the bird lifts
from the perch position that the leg tendons relax the foot's
grip on the limb. In a bat, it is the pull of the weight of the
animal on the tendon that locks the foot on its perch.

Humans find it hard to imagine sleeping in a standing or hanging
position, but that is because the design of our body does not
allow us to be secure in those positions. Such a simple thing
as the position in which we sleep is a reflection of the incredible
design that is built into all living things, but it is just a
small part of the numerous systems which are all necessary for
the survival of life. Attributing such complexity to chance requires
a faith far beyond the belief of a designing God who carefully
provided for all forms of life to live even though the conditions
under which that life exists are highly varied.